SQL formatting seems to try to format /switches in a string value. E.g.
SELECT * FROM MyTable WHERE StrField = N'C:\SomeValue'
The "\S" in the string value "C:\SomeValue" is a different colour than the rest of the string, as if it is interpreting as a switch/parameter.
Observed in DokuWiki version rc2013-10-28 "Binky", which uses GeSHi version 22.214.171.124. String text was red, "\S" was navy blue.